Oilrag,
The Chevrolet 1955-1960 Chevrolet Guardian-Tune for All Models that you linked-to shows 1960 261 and 235 engines both having a timing specification of 5 degrees BTDC.
However, the 1960 Chevrolet Truck Shop Manual shows different specifications for 1960:
ENGINE TUNE-UP 7-16 (Chapter 7, page 16)
Ignition Timing for Thriftmaster 235 = 5 degrees BTDC - Note 1A: first short radial mark clockwise from TDC timing ball
Ignition Timing for Jobmaster 261 = TDC
ENGINE TUNE-UP 7-16, step 22. TEST IGNITION TIMING AND ADVANCE (Chapter 7, page 16)
. . . for correct timing, steel ball in flywheel (261 only) or 5 degree mark (235 only) should line up with the pointer on the flywheel housing . . .
My guess is that the poorly worded last line, above, caused confusion when writing/producing the 1955-1960 Chevrolet Guardian tune?
